<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      let a = 200;
      let b = 400;
      function f1(a, b) {
        // let a=a, b=b;
        console.log("a:", a, "b:", b);
      }

      f1(a, b); // 实参
      console.log(a, b);
    </script>
  </body>
</html>
